HYDRAULIC TRANSMISSION FOR STEAM VALVE, COMBINED STEAM VALVE, AND STEAM TURBINE

摘要

PROBLEM TO BE SOLVED: To provide a hydraulic transmission for a steam valve capable of exerting a uniform brake force on a valve body when closing the valve with a simple structure.SOLUTION: A hydraulic transmission 50 for a steam valve 16 comprises a plurality of hydraulic actuators 52 that create drive power for transmitting to a valve body 32 via a valve stem 34 of the steam valve, and each of the plurality of hydraulic actuators comprises a cylinder, a piston, and a rod with one end connected to the piston and the other end connected to the valve stem. Among the plurality of hydraulic actuators, the main actuator 52A includes a contraction part for regulating pressure oil flow in a hydraulic chamber defined by the cylinder and the piston so as to exert a uniform brake force on a valve body during the closing valve operation of the valve body, hydraulic actuators other than the main actuator include at least one auxiliary actuator 52B without the contraction part, and the hydraulic chamber of the auxiliary actuator is communicated with the hydraulic chamber of the main actuator.SELECTED DRAWING: Figure 2